Stock inlet



Patented Dec. 29, 1953 sroox INLET Lloyd Hornbostel and Edward D.Beachler, Beloit, Wis., assignors to Beloit Iron Works, Beloit, Wis., acorporation of Wisconsin Application July 7, 1949, Serial No. 103,402

Transversely extending baffle or walls within stock inlet boxes are usedin the paper making art in an attempt to quiet stock flow through thebox and to prevent the occurrence of eddy'currents within the stockflowing therethrough. However, such baffles serve to divide the box intoa plurality of stock compartments, and it is known that "dead areas areformed within the separate compartments and that stock rolling can occurwithin the compartments. The paper stock within such dead areas tends tohack and form lumps detrimental to paper quality when later introducedonto the forming wire, whilethe rolling of stock within the separatecompartments interferes with the uniform flow of stock through theinlet, thus aiding in the formation of dead areas. A dead area isparticularly liable to be formed in that region of the inlet box lyingbetween the front bafiles and the slice beneath which stock isdischarged onto the formingwire.

The present invention now provides an improved rectifier rollarrangement for employment within the stock inlet box for a paper makingmachine, the rectifier roll arrangement obviating the necessity ofemploying transversely extending baffles with the attendant operationaldifiiculties heretofore encountered.

In general, the stock inlet of the present invention includes a head boxfor a paper making machine provided with means for introducing stockinto the interior of the box and a stock outlet immediately adjacent theforming wire of the paper making machine. A rectifier roll or a stack ofsuperimposed rolls extends transversely across the interior of the inletto replace the baffle arrangements heretofore employed, while a secondrectifier roll or group of rolls is disposed adjacent the box outletopening to control the flow of stock through the opening onto the papermachine forming wire.

Since the depth of the stock pond in the head box is calculated to givea definite velocity of stock flow in a horizontal path through the boxinto the forming wire, the number of rectifier rolls in the stack andthe size of the rolls will be determined by the desired velocity ofstock flow. Preferably, the depth of stock of the box is held constantby regulated air pressure, the depth being controlled so that anappreciable amount of stock cannot flow over the top rectifier roll inthe stack. The rolls of the stack are spaced apart only sufliciently foroperating clearance and should not provide a flow gap therebetween. Agap of from A; to inch between roll peripheries is satisfactory. Thus,the only restriction to the flow of stock through the box is presentedby the rectifier roll stack, and this resistance to flow is uniformthroughout the entire depth of the stock pond. In this manner, therolling of the stock, the occurrence of dead spots, and the creation ofeddy currents is prevented.

13 Claims. (01.92-44) e 2 The rectifier rolls at the outlet end of thestock inlet are arranged in spaced relation from the outlet opening toform any desired roll pate tern, such as the illustrated arcuatearrangement, which will provide a uniform restriction to the flow stocktoward the outlet. The rolls are grouped so that the stock must flowtherethrough, and each of the rolls extends transversely to the path ofstock flow. By spacing the rectifier rolls of this group from the stockoutlet, any eddy currents generated by the flow of stock through therolls are dissipated prior to introduction of the stock onto the formingwire, and the group arrangement of rolls also preventsthe by-passing ofstock around the rolls onto the formingwire. It is, therefore, animportant object of the present invention to provide an improved stockinlet for a paper making machine in which a uniform flow of stockthrough the inlet is obtained without the employment of solid baflles,walls, or the like.

Another important object of the present invention is to provide animproved stock inlet for a paper making machine'employing a rectifierroll extending transversely to the flow of stock through the inlet toprevent the rolling of stock and the creation of dead areas within theinlet box.

It is a further important object of the present invention to provide animproved stock inlet box having a plurality of rectifier rolls arrangedin spaced relation from the outlet end of the box to present a uniformrestriction to the flow of stock through the outlet, the restrictionbeing transverse to the path of stock flow through the outlet. Stillanother important object of the present invention is to provide animproved stock inlet for a paper making machine having no solidtransverse partitions or baffles therein and presenting a uniformrestriction to the flow of stock therethrough by means of a plurality ofsuperimposed rectifier rolls disposed transversely to the flow of stockthrough the box. Other objects, features and advantagesof this inventionwill become apparent to one skilled in the art from the followingdescription of the embodiments illustratedin the accompanying drawings,in which:

Figure l is a vertical sectional view taken' through a stock inlet boxof thepresent invention; Figure 2 is a sectional view, with parts shownin elevation, taken along the plane II-II of Figure 1; and vFigure 3 isa sectional view taken along the plane III-III of Figure l.

As shown on the drawings: In Figure 1 reference numeral I0 refersgenerally to a stock inlet box having a rear vertical wall II and afront vertical wall l2 terminating in a beveled slice tip l3. A topclosure wall I4,

apertured to receive an air supply line l5, extends between the frontand rear walls H and I2, respectively, the top wall l4 being joined tothe front wall I2 by means of a flexible seal I6. A bottom wall I! isprovided to underlie the top wall [4 in spaced relation thereto, thebottom wall terminating in spaced relation to the sliced tip I3 toprovide an outlet opening l.8 immedi: ately adjacent a paper machineforming wire W- lapped about a breast roll R and terminating short ofthe rear wall I l to provide an inlet opening IS. The walls ll, l2, l4and i1, together with a pair of spaced side closure walls 48, cooperateto define an enclosed space A which may be subjected to air pressurethrough the air supply pipe. I5 connected to a suitable source of airunder pressure.

Stock may be introduced into the space A through the inlet opening l9 byany desirable means, preferably by means of a flow evener through a sumpportion 2| underlying the open.- ing l9 and defined by the baokwall H ofthe box H1 and spaced parallel wall 21a depending from the bottom wallll. The flow evener 1]! includes a box defined by side walls, 22 and 23joined to the sump 21 by sloping upper closure walls 22a and 23a,respectively, and a lower closure wall 24 joining the side walls 22 and23. End closure walls 2,] and 28 (Figure 3) areprovided to form theclosed box 29, The front and rear side walls 2 2 and 2 3 slopediagonally across the width of the box 20 to define tapered flowconduits 29 communicating through the inlet pipes 30, carried by endclosure walls 21 and 28, with a source of stock. The conduits 30 thussupply stock under pressure to the conduits 2 9; which are divided by anupstanding partition wall 3| carried by the bottom closure wall 24 ofthe box 20,

A rectifier roll 32 is journaled in the opposing end walls 21 and 28 toextend across the box 20 in closely spaced position overlying thepartition wall 3|. The rectifier roll is driven bysuitable means, suchas an electric motor (not shown), a driving belt or band 3 3 and apulley 34 mounted onone end of the shaft 35 of the roll. The rectifierroll is provided with a plurality of graduated perforations 36 whichdiminish in capacity inwardly from the ends of the roll, the ends of therolls being scalloped or perforatedwith semiapertures formed by theintersection of the terminal apertures with the. ends of the roll. Theaperture arrangement is. such that a uniform flow rate along the entirelengthor the roll is maintained, and frictional drag or a skin eilect onthe flow of the flowing stock normally imparted by the stationary sidewalls 2:! and 28. of the box 20 is compensated for by the reducedcapacity holes of the mid-section of the roll. The roll is alsoprovided. with a plurality of axially spaced interior baflies 31extending radially across the interior ofv the roll, the bafiles 31serving to direct stock flow radially through the roll.

In accordance with the present invention, the space A of the inlet boxHlisnot provided with transversely extending solid partition walls orbafiles as is customary in the art. Rather, the space A is provided witha plurality of superimposed axially aligned rectifier rollsAO rotatablyjournaled in opposing side walls 0; the box. 10 and adapted to berotated by suitable means, as by means of individual variable speed,reversible electric motors 4|.

The stack ofsuperimposedrectifier rolls, 40 presents auniform estrictionto the-flow. of-stock entering the space. A, through the aperture. [9

4 and introduced onto the forming wire W wrapped about the press roll 3through the outlet orifice l8.

The rolls 40 are spaced apart through the height of the stack, theperipheries of the rolls preferably being about A; to /2 inch apart.This distance is not sufiicient to open a flow path between the rolls,while the rolls are maintained out of peripheral contact to prevent theformation of pressure nips therebetween which might interfere withuniform stock flow through the box. The direction of drive of the rollsrelative to one another is selective to suit conditions and the rollsare preferably; rotated at very low speeds with rotation serving merelyto clean the; holes. e spee of a on ma e a low-a from about 5 to 10 R.P. M., with the holes being cleaned by the reversed fiow through therolls as they are rotated. Thus, flow through the box is; caused by theintroduction of stock under pressure into the box and not by any pumpingaction exerted by the rolls.

It is preferred that the stack of rolls, be of such height that theuppermost roll 40 is substantially submerged within stock flowingthrough the inlet box It). In Figure 1 it may, be seen that the level Bof stock is tangent to the periphery of the uppermost roll 40. Inorderthat the flow characteristics of stock passing through the box 16may be controlled by. the rolls 4D, itis highly undesirable to have anyappreciable amount of stock by-passing the rolls, either by having thestock level above the uppermost roll of the stock or by any other methodor manner of stock flow.

The rolls 40 are substantially identical with the roll 32 herein beforedescribed and are provided with apertures 42 of inwardly decreasingdiameter and interior radial bafiles 43.

In order to maintain stool; level B at a desired height within the spaceA, the box It] is provided with a stock level control comprising a pipe44 providing a vent to atmospheric pressure. The operation of theautomatic level control will be obvious to those skilled in the artinasmuch as when the stock level within the chamber A drops below theopening of the pipe 44, chamber A is vented to atmospheric pressure, andby this lessening of'pressure the stock level in the chamber will beraised by flow from the stock distributor or flow evener 20 ashereinbefore described; When the stock level covers the end of the pipe44, pressure within the box increases and the flow. of stock into thechamber A from the stock distributor is resisted by this increasedpressure. It will be appreciated that a vacuum pump arrangement may alsobe employed'to maintain a constant level of stock within the space A,particularly inconnection with the deposition of:10w level, heavy stockon the forming wire.

Although in the specific embodiment of Figure l a stack consisting ofthree rectifier rolls has been shown, it will be appreciated that thenumber of rolls in the stack and the relative sizes ofthe rolls may bevaried in accordance with the level of stock within the chamber. Undersome conditions it is.-possible to use only one rectifier roll with theheight of the stack and the number of rolls in the stack generallyincreasing in accordance with an increase in desired depth for the pondof stock in the box. Also, it is desired that the height of stock bemaintained at a level sufficiently low to avoid the free flowing ofstock above the top rectifier roll but sufliciently high to preventlocalized whirling agitationsof'the stock by the exposed portion of thetop roll.. A preferred level is tangent to the periphery of thedirections to flow stock uniformly and at a given rate onto the formingwire. The rolls 45 may be so arranged as illustrated so that the portionof the peripheries nearest the slice tip I3 falls on an are 41subtendedby a radius 48 having its center at the stock tip It. The rolls45 are preferably mounted in a bridging arrangement adjacent the outletopening l8 to control the flow of stock from the space A onto theforming wire W. It has been found that one roll positioned adjacent aslice, as heretofore conventionally employed in the art, results in thestreaking of stock deposited on the wire and the formation of fingers onthe wire or a broom effect in the deposited stock.

By the employment of a plurality of rolls, each spaced from the outletopening 18, any turbulence induced in the stock by its passage throughthe rolls 45 is dissipated prior to introduction of the stock onto theforming wire, an even flow through the opening 18 is obtained, and thedevelopment of a dead area of the slice is prevented. 'Io obtain theoptimum results, the uppermost roll of the group of rolls 45 should bebeneath the stock levelB sufficiently to prevent air being pulled intothe stock passing through the roll, while the distance from the roll tothe stock level should be less than that at which a deadarea could beformed above the roll. Preferably the roll 45 should be from 3 to 6inches below the stock level B or below the upper roll 40. i

The bridging arrangement of the rolls 45 also gives an increased outlethole area when compared with the single roll previously employed. Theincreased exit area thus afforded aids in reducin the roll exit velocitynecessary to accommodate a given stock flow rate, thus effectivelyeliminating the squirting" effect otbained in the use of a single roll.

By this arrangement'of rectifier rolls, the rolls are uniformlydistributed between the front wall l2 and the bottom wall I! of the box.The length of the radius 48 is preferably about 10 to 14 inches,depending upon the quantity and type of stock fed through the stockinlet box and the quantity and number of rolls 42. The plurality ofadjacent rolls 45 prevent stock from bypassing the rolls while allowingthe dissipation of any eddy currents which might be caused in the stockby their passage through'the rectifier rolls.

It will be noted that each of the rolls 45 is disposedtransversely tothe flow of stock therethrough from the stock pond onto the formingwire, and that the group of rolls 45 presents a uniform rectifying area,thus preventing any rolling of stock such as would occur by theprovision of a baffle cooperating with a single rectifier roll as isconventional in the art.

It' will, of course, be understood that various details of constructionmay be varied through a wide range without departing from the principlesof this invention, and it is, therefore, not the purpose to limit thepatent granted hereon otherwise than is-necessitated by the scope of theappended claims. T

We claim as our invention:

1. A stock inlet box for a paper machine comprising a head box having aninlet opening at one end for receiving stock from a source and having anoutlet opening at the other end for flowing stock onto the forming wireof a paper making machine, transversely extending rotatable rectifyingmeans mounted within the box in spaced relation from the inlet andoutlet to present a uniform restriction to the flow of stock through thebox while preventing rolling of stock and the formation of dead stockareas within the box, and vent means for maintaining a level of stock inthe box that will submerge the'rectifying means, said rectifier meanspresenting the sole restriction to stock flow through the box. I

2. A stock inlet for a paper making machine Q comprising a head boxhaving an inlet opening at one end thereof for receiving stock'from asuitable source and an outlet opening at the otherend for flowing stockonto a paper making machine, and a plurality of superimposed rectifierrolls mounted in said box and extending transversely to the flow ofstock therethrough to present a uniform andsole restriction to the flowpassage of stock through the box.

3. In a stock inlet box adapted for the flow of stock therethrough, theimprovement which comprises a vertically extending stack of axiallyaligned peripherally spaced rectifier rolls mounted within said box,each roll extending transversely to the path of stock flow through thebox and the stack presenting a uniform and sole restriction to the flowof stock therethrough.

4. In a stock inlet box having an inlet at one end and one outlet at theother end and defining a path adapted for the flow of paper stocktherethrough, the improvement of rotatable rectifier roll meansextending transversely of the path of stock flow to present the solerestriction to stock flow through the box, and a stock level control formaintaining a stock level within the box barely sufficient to completelysubmerge the rectifier roll means to prevent rolling of stock and thecreation of dead areas above the roll means and the drawing of air intothe stock by rotation of the roll means. I

5. A stock inlet box comprising a stock inlet for a paper making machinecomprising a head box having a stock inlet opening at one end thereoffor receiving stock from a suitable source and a stock outlet openingadjacent the other end thereof for flowing stock therefrom onto aforming wire, and a plurality of closely adjacent rectifier rollsextending transversely across the interior of said box adjacent saidoutlet opening and spaced uniformly therefrom to provide a uniformrestriction to the flow of stock through said outlet opening.

6. A stock inlet for a paper making machine comprising a head box havingan inlet opening at one end thereof for receiving stock from a suitablesource and an outlet opening adjacent the other end thereof forintroducing stock onto a forming wire, and a plurality of closelyadjacent rectifier rolls mounted in a bridging arrangement about saidoutlet opening and-in uniformly spaced relation thereto to present auniform re-'- striction to the flow of stock from said, box through saidoutlet opening.

7. A stock. inlet for a paper making machine comprising a head boxhaving an inlet. opening adjacent one. end thereof for receiving stockfrom a source and an outlet opening at the other end for flowing stockonto aforming wire, a slice controlling said. stock outlet opening, anda plurality of arcuately aligned, transversely extending, closelyadjacent rectifier rolls mounted adjacent said outlet end with theirperipheries defining an arc having its center at the tip of said slice,said rolls defining a uniform restriction to substantially the totalflow of stock through said stock outlet opening while being spaced fromsaid opening to accommodate dissipation of any turbulence in the stockafter passage through the rolls and prior to passage through the outletopening.

8. A stock inlet for a paper making machine comprising a head box havingan inlet opening for receiving stock flow from a suitable source and anoutlet opening at the other end thereof for flowing stock onto a fornnngwire, a stack of vertically aligned rectifier rolls positionedintermediate said inlet opening and said outlet opening,

anda. rectifier roll extending transversely of said box adjacent saidoutlet opening and spaced therefrom for presenting a uniform restrictionto the flow of stock from said box through said outlet opening whileaccommodating dissipation of any turbulence in the stock after stock.passage through the rolls and prior to stock passage through the outletopening by virtue of thespacing of the last mentioned rectifier rollfrom the outlet. opening, and said rectifier rolls cooperating to definethe sole restriction to the flow of stock through said box.

9. In a stock inlet for a paper making machine having an inlet openingfor receiving stock from a source and an outlet opening for fiOWlIlgstock from the box onto a forming, wire surface, 9, rectifier rollintermediate said inlet and outlet openings and presenting a uniformrestriction to flow of stock along the length of the box, and apluralityof axially aligned rectifier rolls mounted adjacent said outletopening and having their outer peripheries spaced equally from saidopening to permit the uniform dissipation of turbulence in the stockprior to its exit through said opening, said rectifier rolls cooperatingto define the sole restriction to the flow of stock through said box.

10. A stock inlet box having an, inlet opening for receiving stock froma source and an outlet opening for fiowing stock from the box. onto aforming Wire surface, a vertical stack of transversely extendingrectifier rolls presenting a uniform restriction to the flow of stock tothe box, and a plurality of additional rectifier rolls mounted inarcuate alignment adjacent the outlet opening of said box, saidadditional rolls having their peripheries falling on an arc having itscenter of curvature at said outlet opening said rolls. definmay auniform restriction to substantially the total flow of stock throughsaid stock outlet opening while being spaced from said opening toaccommodate dissipation of any turbulence in the stock after stockpassage through the rolls and prior to stock passage through the outletopening.

11. In a stock inlet box for a paper making machine having an inletopening at one end thereof for-receiving stock from a suitable source,and an outlet opening in the other end thereof for flowing stock onto aforming wire, the improvement which comprisesa verticallyextendingstackof rectifier rolls: extending transversely to the. flowof. stock through; the box. topresent a controlled restriction to stockflow, and means for maintaining stock within the box at a levelsubstantially tangential to the periphery of the uppermost roll of.said. stack of rectifier rolls, the stock level. at the uppermost rollof said stack of rectifier rolls being sufiicient to completely submergesaid stack, thereby preventing rolling of. stock and the creation: ofdead spots above the, stock and the drawing of air into the stock by therotation of the uppermostof'said rectifier roll.

12. A. stock inlet box for a paper machine comprising a; head' box.having generally horizontal floor; with an inlet opening in one endofthe. floor and an outlet opening for the box at the end. opposite thinlet for flowing stock onto a paper machine forming. wire, transverselyextending rotatable stacked rectifier-rolls mounted within. the box inspaced relation from the inlet and outlettopresent a uniform restrictionto the flow of stock through the box while preventing rolling of the.stock and formation of deadstock areas. within the box, and bleed-01flevel control means: suitably mounted, at an aperture inthe head boxaligned with the top of the. uppermost stacked roll for maintainingalevel' of stock in the box that will submerge, all the. stacked rolls,said stacked rolls presenting thev sole restriction to stock flowlongitudinally through the box.

13". A stock inlet for a. paper making machine comprising. a.balile-less, horizontally-floored head box having an inlet. opening. atone end. of the floor for-receiving thestock from a suitable source andanoutlet opening in the. box at the opposite end thereof for flowingstock onto a paper making. machine forming wire, a plurality ofsuperimposed rectifier rolls mounted in. said box and extendingtransverselyto the flow of stock therethrough. to present a uniform: andsole restriction to the flow passage of. stock through thebox andavertically extending apertured side wall for said head box, beingsuitably apertured to afford bleed off means for. maintaining alevel ofstock in the box that will submerge the roll.

LLOYD HORNBOSTEL. EDWARD D. BEACHLER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,526,193 Voith Feb. 10, 1925 1,629,088 Aldrich May 17, 19271,727,928 Berry Sept. 10, 1929 2,027,611 Niks Jan. 14, 1936 2,060,808Kellett et a1. Nov. 17, 1936 2,062,471 Murray Dec. 1, 1936 2,381,286Hornbostel Aug. 7, 1945 2,394,509 Boettinger Feb. 5, 1946 2,396,695Goodwillie Mar; 19, 1946 2,509,822 Hornbostel May 30, 1950 2,550,552Goodwillie Apr. 24, 1951 FOREIGN PATENTS Number Country Date 306,845Great Britain July 25, 1930 OTHER REFERENCES Tappi, Dec. 26, 1940,Headbox and Slice Designs for Newsprint Machines, pages 323 to 327,pages 325 and 326 pertinent.

Bearce, Technical Assn. Papers, Series XVIII. page 314.

